1. Field of the Invention
The present invention relates to a synthetic resin compound having excellent thermal and chemical resistance, and excellent mechanical characteristics, wherein the synthetic resin is applicable to a wider variety of molding methods and end-purposes than those of the known art.
2. Description of the Related Art
Poly(ether-ether-ketone)s are known as engineering plastics having excellent thermal and chemical resistances, and excellent mechanical characteristics.
These polymers, however, have a characteristic of high crystallinity, and therefore, they are insoluble in organic solvents.
As a result, only extrusion molding or compression molding can be employed as a molding method for manufacturing various products from these polymers. In other words, the products which can be manufactured by using these polymers are limited.
Accordingly, various research has been performed with the view to make the polymers soluble in organic solvents, and as a result, alkyl-substituted aromatic poly(ether-ketone)s have been developed. Since these alkyl-substituted aromatic poly(ether-ketone)s can be dissolved in various organic solvents, they have been used in many fields; for example, they have been used as common varnish.
These alkyl-substituted aromatic poly(ether-ketone)s soluble in organic solvents are, however, inferior in chemical and solvent resistances, and therefore, cannot be used for products which require these characteristics of the resistance.
J. de. Abajo, et al. reported in POLYMER, Vol.33, No.15, pp.3286-3291 (1992) about a resin compound which was improved in chemical and solvent resistances. This resin compound is produced by the following reaction formula 1. ##STR1##
The above reaction consists of the known Schotten-Baumann reaction, i.e. acylating reaction between 3- or 4-ethynylbenzoylchloride and diol of an aromatic ether-ketone.
The resin compound produced from the above reaction, however, remains insufficiently soluble in the type of organic solvent generally used, and accordingly, molding method options are limited when this resin compound is used.
Further, the resin compound has a structure comprising ester linkages since the Schotten-Baumann reaction is utilized to introduce acetylene groups. As a result, the resin compound is highly moisture-absorptive and tends to be low moistureproof, and in addition, tends to be hydrolyzed by, for example, contact with water vapor. Moreover, since the resin compound is not a polymer, degree of crosslinking cannot be controlled.
Meanwhile, T. M. Miller, et al. reported in Macromolecules, Vol.26, pp.2935-2940 (1993) about a polymer which is produced by the following reaction formula 2. ##STR2##
The resultant polymer is produced from an acetylene-terminated aromatic ether monomer and an acetylene-terminated aromatic ketone monomer by using tetramethylethylenediamine, a copper catalyst, or the like.
Such a polymer, however, has some drawbacks. For example, solubility in organic solvents becomes low as the molecular weight of the polymer increases. In addition, control of the polymer molecular weights is not easy. Although the polymer has a ketone group, the polymer has no ether linkages. This causes the principal chain of the polymer to be stiffer, the polymer to be easily dissolved in a solvent, and crosslinking to not easily progress. Moreover, since the curing temperature of the polymer is 300.degree. C. or higher, the polymer rarely can be used in view of the limited thermal capability of furnaces ordinarily used.